To say that something is "ineffable" means that it cannot or should not, for overwhelming reasons, be expressed in spoken words. It is generally used to describe a feeling, concept or aspect of existence that is too great to be adequately described in words, or that inherently (due to its nature) cannot be conveyed in dualistic symbolic human language, but can only be known internally by individuals.

Quotations

:"Whereof one cannot speak, thereof one must be silent." - Ludwig Wittgenstein
:"If a person can't communicate, the very least he can do is to shut up." - Tom Lehrer
:"What cannot be spoken in words, but that whereby words are spoken." - Kenopanishad
:"We shall grapple with the ineffable, and see if we may not eff it after all." - Douglas Adams in Dirk Gently's Holistic Detective Agency
:"There IS a Crab of Ineffable Wisdom." - Stephanie Semmler

In Zen it is often said that (by analogy) the finger can point to the moon but is not the moon; likewise words and actions can point towards what is ineffable but cannot make another know it.

Things said to be ineffable

* The Tetragrammaton, or Yahweh (by orthodox Jewish tradition)
* Names of various villains in works of fiction, e.g. Lord Voldemort in the Harry Potter books, the Dark One in The Wheel of Time, Melkor and Sauron in The Silmarillion and The Lord of the Rings, Hastur in the Cthulhu Mythos, as well as Yawgmoth in Magic: The Gathering
* The "Will of Bob" in Mostly Harmless, part of The Hitchhiker's Guide to the Galaxy
* The nature of qualia (sensory experiences), such as colors or flavors
* The nature of spiritual experiences, e.g. Søren Kierkegaard's analysis of Abraham in Fear and Trembling, Problemata III, and in particular the mystic's realization of nonduality.
*The human soul (see also sentience and the Hard problem of consciousness)
*The musical experience, following Theodor Adorno, Vladimir Jankélévitch, among others.
*In C.S. Lewis' novel The Magician's Nephew, there is a word, referred to as the deplorable word, which ends all life on the planet it is spoken on. Jadis uses it on her own home world of Charn.
* The pre-big bang universe (as it was "nothing" to a much greater point than a human being could understand)
* A universe which has five or more dimensions (our universe being four dimensional, the first three being movement and the fourth being time).

Category:Philosophical terminology
Category:Religious philosophy and doctrine